After a disappointing June which witnessed a 48% drop in monthly rainfall in Kerala, the State appears to be staring at a bleak July as well with the monthly forecast issued by the India Meteorological Department (IMD) for July indicating below-normal rainfall in some parts of the southern peninsula.
A senior scientist attached to the IMD said, like in the previous year, the State is likely to receive below-normal rainfall in July. In the last three consecutive years, the State received deficient rainfall in the months of June and July.
The absence of rain-bringing cyclonic systems such as low pressure or depressions in the Bay of Bengal and the Arabian Sea is one of the main reasons for the low precipitation. Normally, an average of three cyclonic systems used to form by this time every year.
However, despite Cyclone Asani, the first cyclonic storm over the North Indian Ocean during this calendar year, no major systems formed this year, both in the Bay of Bengal and the Arabian Sea, although high-intensity cyclonic systems are relatively less in the Arabia Sea owing to the lower sea surface temperature (SST) and unfavourable wind shear, compared to the Bay of Bengal. Further, westerly wind flow from the Arabian Sea to the South Peninsular India in lower tropospheric levels is yet to gain significant strength.
Similarly, though the La Niña conditions are likely to continue during the remaining part of the monsoon season, the latest forecasts from global models indicate that negative Indian Ocean Dipole (IOD) conditions are likely to develop during the remaining part of the monsoon season, which is expected to have a direct bearing on the monsoon.
Yellow alert
A low pressure area is likely to form over north Odisha and its neighbourhood around Monday, which is likely to enhance the rain activity in Kerala for a few days. However, high-intensity rainfall is unlikely, according to weather experts.
The weather models issued by the IMD sounded a yellow alert in Kerala for the next four days except in Thiruvananthapuram, Kollam and Pathanamthitta districts, while warning of isolated heavy rains. As per the long-period track record of Kerala, the State used to receive the highest rainfall in July with 72 cm of rain, followed by June (64 cm), August (43cm) and September (26 cm).
